Histochemical study of proventriculus in pre-hatch and post-hatch days in northern bobwhite quail (Colinus virginianus)

The present study was designed to investigate the histochemical developmental changes of the proventriculus at pre-hatching and post-hatching in the northern bobwhite quail at periods 11- and 15-days pre-hatching in addition to 14- and 21-days post-hatching. The proventriculus composed of four tunics is tunica mucosa, tunica sub-mucosa, tunica muscularis, and tunica serosa. The tunica mucosa was lined with simple columnar epithelium and the height of epithelium increases with the age also the thickness of the mucosa, the tunica submucosa filled with proventricular glands at 14- and 21-day post-hatch and the gland was height in diameters while in 11- and 15-day pre-hatch the gland less in diameter and the sub mucosa does not fill with the gland. Tunica muscularis was thicker in post-hatch than in pre-hatch, 11- and 15- day pre-hatch composed of a thin inner circular layer and thick outer longitudinal layer but in 14- and 21-day post-hatch the tunica muscularis was composed of a thin inner and outer circular layer and thick middle longitudinal layer. The mucosa and proventriculus glands give a positive reaction for Alcian blue stain and a weak to moderate reaction for periodic acid Schiff stain at pre-hatch, while at post-hatch the mucosa gives a positive reaction for Alcian blue stain and a negative reaction for periodic acid Schiff stain and the proventricular glands give a positive reaction for Alcian blue and periodic acid Schiff stains.